1. Field of the Invention.
This invention relates to the synthesis of 2,6 -bis(dimethylamino)pyridine, 2,6-bis(methylamino)pyridine, to their use as lasing dyes and, more generally, to the use of other similar compounds as lasing dyes.
2. Description of the Prior Art.
It is a well known fact that certain dyes will lase. At the present time, there is a considerable amount of research going on in efforts to find stable dyes which will lase in the ultraviolet region of the spectrum. Dyes with the ability to lase in the ultraviolet are useful in processes being developed for the separation of isotopes. Dyes which will lase in the ultraviolet are, however, rare and, to the best of the inventor's knowledge, it has not been previously known that the dyes disclosed herein will lase in the ultraviolet region.
2,6-Bis(methylamino)pyridine, one of the dyes whose preparation is disclosed herein, has been prepared before. Its preparation was described by Bernstein, Stearns, Shaw and Lott in the Journal of the American Chemical Society, Vol. 69, pages 1151-1158 (1947). Bernstein et al prepared the compound by reacting 2,6-dibromopyridine with an aqueous solution of methylamine for 8 hours in a bomb at 190.degree.C. Bernstein et al obtained a 59% yield and disclosed the compound to have some antiparasitic activity when tested against P. Lophurae in ducklings.
No preparation of 2,6-bis(dimethylamino)pyridine (the other dye whose preparation is disclosed herein) is, insofar as is known by the inventor, given in the literature. A search of Chemical Abstracts revealed the use of 2,6-bis(dimethylamine)pyridine as a starting compound in the synthesis of perchlorinated cyano compounds (U.S. Pat. No. 3,711,480) but failed to reveal any synthesis for the compound. That is, U.S. Pat. No. 3,711,480, while it discloses the use of 2,6-bis(dimethylamino)pyridine, does not disclose a preparation for it and the inventor could not find a preparation disclosed elsewhere.